[PATCH 1/3] KVM: x86: Do not return soft events in vcpu_events

Jan Kiszka
2010-02-15T09:46:00Z

To avoid that user space migrates a pending software exception or
interrupt, mask them out on KVM_GET_VCPU_EVENTS. Without this, user
space would try to reinject them, and we would have to reconstruct the
proper instruction length for VMX event injection. Now the pending event
will be reinjected via executing the triggering instruction again.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
arch/x86/kvm/x86.c | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 86b739f..50d1d2a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2121,14 +2121,17 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
{
vcpu_load(vcpu);

- events->exception.injected = vcpu->arch.exception.pending;
+ events->exception.injected =
+ vcpu->arch.exception.pending &&
+ !kvm_exception_is_soft(vcpu->arch.exception.nr);
events->exception.nr = vcpu->arch.exception.nr;
events->exception.has_error_code = vcpu->arch.exception.has_error_code;
events->exception.error_code = vcpu->arch.exception.error_code;

- events->interrupt.injected = vcpu->arch.interrupt.pending;
+ events->interrupt.injected =
+ vcpu->arch.interrupt.pending && !vcpu->arch.interrupt.soft;
events->interrupt.nr = vcpu->arch.interrupt.nr;
- events->interrupt.soft = vcpu->arch.interrupt.soft;
+ events->interrupt.soft = 0;

events->nmi.injected = vcpu->arch.nmi_injected;
events->nmi.pending = vcpu->arch.nmi_pending;
--
1.6.0.2